US President Donald Trump has accused Attorney General Jeff Sessions of damaging the midterm re-election chances of two Republican members of Congress by prosecuting them.
The justice department's decision to file charges against the men put "easy wins" in doubt, Mr Trump tweeted.
One is accused of insider trading and the other of campaign violations.
The tweet has sparked fresh criticism that Mr Trump is illegally seeking to interfere with the justice system.
The president has often clashed with Mr Sessions over the inquiry into claims that Russia tried to help him win the 2016 election.
The attorney general has recused himself from the investigation led by special counsel Robert Mueller, which includes allegations of obstruction of justice by Mr Trump.
Mr Trump has repeatedly described the inquiry as a "witch hunt".
The latest presidential criticism of Mr Sessions came with just over two months to go before the midterm elections on 6 November. The Democrats are seeking to wrest control of the House of Representatives from the Republicans.
In a tweet, Mr Trump criticised the prosecution of "two very popular Republican Congressmen".
Last month Representative Christopher Collins was charged with participating in an insider trading scheme. He has denied wrongdoing but said he would not seek re-election.
Later in August Representative Duncan Hunter and his wife were indicted for allegedly using campaign funds to pay for personal expenses. They too deny the charges.
The investigation into Mr Hunter began under the presidency of Barack Obama, but the Collins inquiry was launched last year.
Both men were early supporters of Mr Trump when he launched his bid for the presidency.
The justice department has not commented on the tweet. But it has drawn fire from a number of critics, including Mr Trump's fellow party members.
Republican Senator Ben Sasse said the justice department should remain politically neutral in deciding whether or not to prosecute.
"The United States is not some banana republic with a two-tiered system of justice – one for the majority party and one for the minority party. These two men have been charged with crimes because of evidence, not because of who the president was when the investigations began."
US political scientist and columnist Brian Klass called Mr Trump's outburst "insane".
Other critics argue that midterm elections are not a good reason to delay prosecution.
BBC
